Tensile testing of SiC-based hot gas filters at 600°C water vapour

Tensile testing at 600°C water vapour environment of SiC-based aluminous alkaline silicate bonded hot gas filters is reported. Tests were completed with as-received material and with material exposed 455 hours in water vapour at 850°C and thermal cycles. A deep notch was needed to guide the fracture to the mid section, and FE analysis of the notch geometry with ABAQUS CAE was also preformed. The fracture surfaces were investigated with optical and scanning electron microscopy and compared with fracture surfaces of room temperature tests. Sub-critical crack growth may have occurred in some of the water vapour exposed specimens, but the measured strength at the displacement rate of 0.002 mm/s was not significantly different from that at the rate of 0.02 mm/s.